<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<link rel="stylesheet" href="../common.css">
<style>
    body {
        background-color: #222;
        overflow: hidden;
    }

    .box {
        background-color: orange;
        height: 100px;
        width: 100px;
        border-radius: 100%;
        position: relative;
    }

    .circle {
        position: absolute;
        background-color: inherit;
        height: 100%;
        width: 100%;
        border-radius: 100%;
        opacity: 0.8;
        -webkit-animation: wave 2s ease-out infinite;
        animation: wave 2s ease-out infinite;
    }

    .circle:nth-of-type(1) {
        -webkit-animation-delay: -0.5s;
        animation-delay: -0.5s;
    }

    .circle:nth-of-type(2) {
        -webkit-animation-delay: -1s;
        animation-delay: -1s;
    }

    .circle:nth-of-type(3) {
        -webkit-animation-delay: -1.5s;
        animation-delay: -1.5s;
    }

    @-webkit-keyframes wave {
        100% {
            transform: scale(1.75);
            opacity: 0;
        }
    }

    @keyframes wave {
        100% {
            transform: scale(1.75);
            opacity: 0;
        }
    }
</style>

<body>
    <div class="box">
        <div class="circle"></div>
        <div class="circle"></div>
        <div class="circle"></div>
        <div class="circle"></div>
    </div>
</body>

</html>